The 3GPP LTE is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.
Small cells using low power nodes are considered promising to cope with mobile traffic explosion, especially for hotspot deployments in indoor and outdoor scenarios. A low-power node generally means a node whose transmission power is lower than macro node and base station (BS) classes, for example pico and femto evolved NodeB (eNB) are both applicable. Small cell enhancements for evolved UMTS terrestrial radio access (E-UTRA) and evolved UMTS terrestrial radio access network (E-UTRAN) will focus on additional functionalities for enhanced performance in hotspot areas for indoor and outdoor using low power nodes.
In next generation wireless communication systems, a situation, in which a channel condition for a user equipment (UE) improves relative to an existing environment by e.g. small cell deployment or a next-generation interference management scheme (e.g. network-assisted interference cancellation and suppression (NAICS)), may be considered. In this case, introduction of high order modulation, like 256 quadrature amplitude modulation (QAM), may be considered as a part of improvement of spectral efficiency. Therefore, a method for supporting the higher order modulation efficiently may be required.